The hollow fiber dialyzer is a well known commercial capillary fiber diffusion device, which is sold by several companies and covered by numerous patents. One commercially available version of the hollow fiber dialyzer is the CF Capillary Fiber Dialyzer sold by Travenol Laboratories, Inc.
This family of dialyzers comprises a bundle of hollow capillary fibers made of a cellulose-based material, retained in a tubular housing so that a first flow path is defined through the bores of the fibers in the bundle, and a second flow path extends through the bundle between the capillary fibers.
In the event where the device is a dialyzer for blood, the blood typically passes through the first flow path through an axially disposed inlet with respect to the bundle.
The dialysis solution then passes through the second flow path in contact with the exterior surface of the capillary fibers.
During the assembly process, which requires the assembly of a bundle containing several thousand capillary fibers, it is not infrequent for one more of the capillary fibers to break or otherwise form a leak, so that there is a communication between the first and second flow paths. This may be discovered on testing, and renders the capillary fiber diffusion device useless, since the blood can then pour through the broken fiber into the dialysate flow path which is, of course, unacceptable.
If the fiber could be repaired or eliminated from the bundle, the remaining thousands of capillary fibers would remain capable of providing effective dialysis or other diffusion as is desired, but this has, of course, proven to be impossible since finding and repairing the one or two defective fibers in the bundle is similar to the famous situation of finding a needle in the haystack. Also, it is practically impossible to remove the defective fibers without disrupting the bundle, even if they could be found.
In accordance with this invention, a technique is found for reliably repairing leaks in the bundle of capillary fibers of a diffusion device by inactivating the few defective fibers, while permitting the remaining intact fibers to continue to be operational.
The invention of this application may be used with any hollow fiber diffusion device, including particularly dialyzers for blood, but also including hollow fiber oxygenators, ultrafiltration devices, membrane plasmapheresis devices, and other devices. The membrane plasmapheresis device is used to extract plasma from whole blood by permitting the plasma to pass through an appropriate and well known type of membrane, while preventing the blood cells from passing therethrough.